diff --git a/pygments.rb.gemspec b/pygments.rb.gemspec
index 324adc9..358947e 100644
--- a/pygments.rb.gemspec
+++ b/pygments.rb.gemspec
@@ -26,7 +26,7 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'rake', '~> 13.3.0'
   s.add_development_dependency 'rubocop', '~> 1.77.0'
-  s.add_development_dependency 'test-unit', '~> 3.6.0'
+  s.add_development_dependency 'test-unit', '~> 3.7.0'
 
   s.files = `git ls-files -z`.split("\0").reject { |f| File.symlink?(f) }
 end